The present invention relates to systems and methods for building three-dimensional (3D) objects. In particular, the present invention relates to rapid prototyping/manufacturing systems and methods for building 3D objects with layer-based additive techniques.
Rapid prototyping/manufacturing systems are used to build 3D objects from computer-aided design (CAD) models using one or more layer-based additive techniques. Examples of commercially available layer-based additive techniques include fused deposition modeling, ink jetting, selective laser sintering, electron-beam melting, and stereolithographic processes. For each of these techniques, the CAD model of the 3D object is initially sliced into multiple horizontal layers. For each sliced layer, a build path is then generated, which provides instructions for the particular rapid prototyping/manufacturing system to form the given layer. For deposition-based systems (e.g., fused deposition modeling and ink jetting), the build path defines the pattern for depositing roads of build material from a moveable deposition head to form the given layer. Alternatively, for energy-application systems (e.g., selective laser sintering, electron-beam melting, and stereolithographic processes), the build path defines the pattern for emitting energy from a moveable energy source (e.g., a laser) to form the given layer.
For example, in a fused deposition modeling system, build material is extruded from a moveable extrusion head, and is deposited as a sequence of roads on a substrate in an x-y plane based on the build path. The extruded build material fuses to previously deposited build material, and solidifies upon a drop in temperature. The position of the extrusion head relative to the substrate is then incremented along a z-axis (perpendicular to the x-y plane), and the process is then repeated to form a 3D object resembling the CAD model.
In fabricating 3D objects by depositing layers of build materials, supporting layers or structures are typically built underneath overhanging portions or in cavities of objects under construction, which are not supported by the build material itself. A support structure may be built utilizing the same deposition techniques by which the build material is deposited. The host computer generates additional geometry acting as a support structure for the overhanging or free-space segments of the 3D object being formed. The support material adheres to the build material during fabrication, and is removable from the completed 3D object when the build process is complete.
While layer-based additive techniques provide durable 3D objects with high resolutions, there is an increasing demand for 3D objects containing embedded inserts, where the embedded inserts are not necessarily fabricated with the layer-based additive techniques. For example, consumers may request 3D objects containing pre-inserted bolts for allowing the 3D objects to be subsequently secured to other components. Currently, embedded inserts are manually inserted in 3D objects during the build operations, which reduces build efficiencies and may result in lower-accuracy placements of the embedded inserts. As such, there is a need for systems and methods for placing inserts in 3D objects during the build operations with layer-based additive techniques.